The same thing happens with the Homehub, just tried it. This has happened before but then gone away. I have ruled out the wifi as the issue by streaming a film from my PC to my Ipad 3 using wifi. There are no disconnects it streams fine so it must be an Internet problem. My area code is not listed as affected on the status page either though, my IP address is also the same sand hasn't changed.
It's likely you've already tried this, but if you haven't already done so, I would suggest that you change your DNS server settings to either Google, or OpenDNS.